Abstract
To investigate how photo-oxidative stress and utilization of nutrients affect leaf senescence, Quercus crispula seedlings were grown under combined conditions of light (100 umol m-2 s-1: low, 1000 umol m-2 s-1: high), temperature (25C: high, 15C or 10C: low), with or without nutrients supply. Fv/Fm was low in plants grown under high light and low temperature. Under high light and high temperature, Fv/Fm was lower in plants without nutrients than those with nutrients. Without nutrients, xanthophylls increased gradually in plants grown under high light and low temperature. The de-epoxidation rate of xanthophylls was higher in plants grown under high light and low temperature, regardless of nutrients supply. In addition, de-epoxidation rates gradually increased in plants under low light without nutrients, resulting in the similar values to those under high light. It was suggested that the translocation of nutrients increased photo-oxidative stress in senescing leaves in plants without nutrients.
